1. Field of the Invention
This invention relates to an information recording/reproduction apparatus and an information recording/reproduction method as well as to a transmission medium. More particularly, it relates to an information recording/reproduction apparatus and an information recording/reproduction method adapted to control the position of the recording/reproduction position of the apparatus by means of the number of pulses output to the stepping motor thereof as well as to a transmission medium adapted to be used with such an apparatus and/or such a method
2. Prior Art
Information recording/reproducing apparatus adapted to record information on or reproduce information from an optical disk by irradiating it with a laser beam from an optical pickup are known.
Known information recording/reproduction apparatus record information or reproduce information from an optical disk by referring to a reference position where the optical pickup can access a lead area. In the information recording/reproduction apparatus, the optical pickup is moved to that position by causing it to move to the innermost periphery of the optical disk, detecting the optical pickup by means of a detection switch fitted to the innermost periphery of the optical disk and subsequently moving the optical pickup toward the outer periphery of the optical disk by a predefined quantity.
It is necessary for the information recording/reproduction apparatus to move the optical pickup to a predetermined position in order not to prevent the information on a so-called CD-R optical disk from being destroyed by heat produced by the laser beam when determining the type of the optical disk to be operating with it. Additionally, it is necessary for the information recording/reproduction apparatus to move the optical pickup in order to output any tracking error without fail when regulating the tracking balance.
However, since known information recording/reproduction apparatus are not adapted to control the position of the optical pickup, it is necessary to firstly move the optical pickup to the innermost periphery of the optical disk each time the optical pickup is moved to the reference position where it can access the lead area. Then, each time the optical pickup is moved to the innermost periphery of the optical disk, the stepping motor driving the optical pickup becomes out of step and emits a sound of collision. This known method is accompanied by an additional problem that the process of moving the optical pickup from the innermost periphery of the optical disk toward the outer periphery thereof is time consuming. Still additionally, an information recording/reproduction apparatus comprising an optical pickup that emits such a sound of collision is not xe2x80x9cdecentxe2x80x9d and it is not pleasant for the user to hear such a noise.
On the other hand, it is necessary to move the optical pickup to a predetermined position in order to determine the type of the optical disk and regulate the tracking balance. Since known information recording/reproduction apparatus are not adapted to control the position of the optical pickup, it is necessary to issue a command to the servo controller to make the system controller move the optical pickup anew after the completion of the operation of determining the type of the optical disk and regulating the tracking balance. This process is rather cumbersome and time consuming.
In view of the above identified problems, it is therefore the object of the present invention to provide an information recording/reproduction apparatus and an information recording/reproduction method that are adapted to quickly move the optical pickup to a desired position on the optical disk being used with it without emitting any sound of collision even after the completion of the operation of determining the type of the optical disk and regulating the tracking balance. Another object of the present invention is to provide a transmission medium adapted to be used with such an apparatus and/or such a method.
According to the invention, the above objects are achieved by providing an information recording/reproduction apparatus comprising a head supported by a support member so to move in a radial direction of the disk being used with it in order to record information on or reproduce information from the disk, said apparatus being adapted to move the head by a predetermined distance in a radial direction of the disk to a first position by means of a drive signal, detecting the first position of the head in terms of the radial direction of the head by means of a position detecting means and controlling the movement of the head by means of the drive signal, using the first position detected by the position detecting means as reference.
Thus, according to the invention, the optical pickup is required to be moved to the innermost periphery of the optical disk only once at the time of initialization of the apparatus in order to define a reference point for the movement of the optical pickup. Thereafter, it is no longer necessary to move the optical pickup to the innermost periphery. Thus, the time required for the optical pickup to be moved to the reference position can be minimized and the sound of collision emitted when the optical pickup is moved to the innermost periphery of the optical disk is eliminated.